Distinct association between APOE ε2 and Aβ in Alzheimer- and vascular-type cognitive impairment

Objective: To investigate the association between apolipoprotein E (APOE) genotype and amyloid-β (Aβ) burden, as measured by PET in patients with subcortical vascular cognitive impairment (SVCI) and those with Alzheimer’s disease-related cognitive impairment (ADCI). Methods: This was a cross-sectional study of 310 patients with SVCI and 999 with ADCI. To evaluate the effects of APOE genotype or diagnostic group on Aβ-positivity, we performed multivariate logistic regression analyses. Further distinctive underlying features of latent subgroups were examined by employing a latent class cluster analysis approach. Results: In comparison with ε3 homozygotes, in the ADCI group, ε2 carriers showed a lower frequency of Aβ-positivity (odds ratio [OR] 0.43, 95% CI 0.23–0.79) while in the SVCI group, ε2 carriers showed a higher frequency of Aβ-positivity (OR 2.26, 95% CI 1.02–5.01). In particular, we observed an interaction effect of ε2 carrier status and diagnostic group on Aβ-positivity (O...